DESCRIPTION: Liver injury such as fibrosis and cirrhosis often directly or indirectly causes death. Conventional treatments- usually small-molecule drugs-do not cure severe liver injury, and although these agents provide great benefit in patients, some are also toxic to the liver. Therefore, there is an urgent need to develop effective, nontoxic therapies that prevent and/or reduce liver injury. In the current application, we propose investigating an unconventional approach to treating liver injury, namely, non-viral, low-electric-field electroporation delivery o interleukin-30 (IL-30) gene therapy. We will use IL-30 because our previous studies revealed that its expression is high in healthy human livers but low in cirrhotic livers (see the pub in Hepatology in Appendix I), suggesting that this cytokine is a natural and physiological hepatoprotectant. Indeed, our preliminary results show that IL-30 can inhibit inflammation-induced liver injury in a murine model by possibly causing the apoptosis of the activated stellate cells, which reduces the production source of inflammatory cytokines and fibrosis-forming collagen. We will use electroporation to deliver IL-30 gene therapy because we and others have found that electroporation is a very effective method of delivering DNA into muscles and skin. Furthermore, clinical tests have shown that electroporation can be used to safely deliver vaccines and anticancer gene therapy. Therefore, electroporation delivery of IL-30 gene therapy has great potential to be translated into the clinic. The proposed investigation of the biological mechanism of IL-30's action will lay the foundation for combining IL-30 gene therapy with other approaches to successfully treat liver disease in the future. Our central hypothesis is that low-electric-field electroporation delivery of IL-30 gene therapy reduces and repairs liver injury without causing liver toxicity and that this liver injury reduction and repair is through IL- 30's activation of the NKG2D ligand-NKG2D receptor-mediated death of fibrosis progenitor cells. To test our hypothesis, we will pursue the following two specific aims. Aim 1: Utilize skin-based, low electric field-mediated electroporation delivery of IL-30 gene therapy for treating chronic liver injury. Aim 2: Determine the biological mechanisms underlying the action of IL-30 gene therapy in reducing liver injury. The successful completion of these aims will identify a simple, practical potentially effective method of gene therapy delivery; enable us to translate IL-30 gene therapy to clinical testing in the future; and reveal a novel mechanism by which IL-30 inhibits liver injur. This novel treatment may complement standard therapies to repair liver injury currently believed to be incurable.